Systems are known, such as the application known by the name “Google Earth” (registered trademark), which supply 3D images. This application is based on the compilation of images in two dimensions, or 2D images, coming from diverse sources and only rarely updated, typically at intervals of several years.
Optical or radar observation systems exist that are programmed to cover, in one or more passes, geographical areas of the order of 10,000 km2. Such a solution is not global, because it only covers small parts of the surface of the Earth.
There also exist specific one-off global missions covering virtually all of the exposed land masses, within a single mission of short duration. These systems do not allow the periodic updating of the information, and do not cover the range of optical imaging in the visible range with high resolution (resolutions of a few tens of cm to a few meters).
There also exist radar missions, referred to as ‘tandem missions’, composed of two radar satellites travelling in formation. These solutions do not allow the periodic updating of the information, and do not cover the range of optical imaging.